The invention relates generally to surgical suture management and more specifically to a percutaneous suture management system and method, more specifically for suture fixation of tissue, through procedures such as for example open and arthroscopic surgeries.
Arthroscopic suturing techniques and instruments have been developed in order to facilitate the suturing of tissue during arthroscopic surgical procedures. In arthroscopic surgery, access to a surgical work site within a patient's body is normally provided through one or more portals formed directly in the patient's body or through one or more cannulas inserted into the body of a patient through small incisions. A chosen surgical procedure is carried out by a surgeon through the use of elongated instruments inserted through these cannulas and it often becomes necessary to suture selected tissue at the surgical work site.
Since the work site is only accessible through a small portal or cannula and since it is very difficult to tie sutures within the body, various devices and techniques have been developed to enable the surgeon to manipulate sutures arthroscopically. For example, some procedures enable the surgeon to pass suture material through selected tissue, form a surgical knot extracorporeally and then move the knot with a knot pusher through the portal or cannula into position adjacent the desired tissue to be sutured. Some cannula instruments used to pass the suture incorporate a hollow needle provided with some structure, often a wire loop, to guide the suture through the tissue pierced by the needle, with the needle extended through a cannula. It is known to use a non-metallic suture shuttle having loops on opposite ends for passing through the bore of a roller type suture passing device. In some cases, each loop of the suture shuttle includes a short leader portion in the form of a single strand monofilament for threading the suture shuttle through the bore of the elongated instrument. In other cases, the short leader portion is eliminated, and the surgeon must squeeze the leading loop together to insert the shuttle into the bore of the elongated instrument.
These instruments are typically available for use exclusively through the cannula and because cannula placement locations are limited, the ability of a surgeon to place and tie each suture at optimum locations is constrained, both by placement of the cannula as well as limitations of working exclusively through the cannula when placing and tying each suture. For example, when working through a cannula or similar portal, a surgeon may have about forty degrees of freedom from a central axis of the portal in which to locate and place sutures. When it is necessary or desirable to locate sutures outside of this limit, then the surgeon must weigh the disadvantages of adding another portal/cannula in an appropriate location against the advantages of positioning the suture at the optimum location. Sometimes such a suture is not used or it is located sub-optimally because the disadvantages predominate. In instances in which it would be desirable to position or distribute sutures through a wide range of angles, it becomes impractical to use arthroscopic techniques due to the relatively large number of portals/cannulas that are required.
A shape memory alloy (SMA) (also known as memory metal or smart wire) is a metal that remembers its geometry. After it is deformed, it regains its original geometry by itself during heating (one-way effect) or, at higher ambient temperatures, simply during unloading (pseudo-elasticity). Main types of SMA include copper-zinc-aluminum, copper-aluminum-nickel, and nickel-titanium (NiTi) alloys. NiTi alloys are generally more expensive and possess superior mechanical properties when compared to copper-based SMAs. The nickel-titanium alloys were first developed in 1962-1963 by the Naval Ordnance Laboratory and commercialized under the trade name Nitinol (an acronym for Nickel Titanium Naval Ordnance Laboratories). Metal alloys are not the only thermally responsive materials, as shape memory polymers have also been developed, having become commercially available in the late 1990's. There is another type of SMA called ferromagnetic shape memory alloys (FSMA), that change shape under strong magnetic fields. These materials are of particular interest as the magnetic response tends to be quicker and more efficient than temperature-induced responses. Shape memory alloys are able to show an obviously elastic deformation behavior which is called Mechanical Shape Memory Effect or Superelasticity. This deformation can be as high as 20× of the elastic strain of steel.
In surgery, percutaneous pertains to any medical procedure where access to inner organs or other tissue is done via a puncture or a piercing of the skin, rather than by using an “open” approach where inner organs or tissue are exposed (typically with the use of a scalpel or blade to make an incision) or through a cannula or other portal.
What is needed is an apparatus, system, and method for enabling a surgeon to quickly and accurately position a suture at any desired location and optionally along a preferred suture pathway without undue constraint by cannula or other portal systems.